An automatic transmission includes a number of gear elements and clutches that selectively couple a transmission input shaft with a transmission output shaft. The various clutches are selectively engaged to establish a desired output speed ratio. Clutch engagement is typically achieved via a controlled application of fluid pressure which moves a clutch piston from an initial position into engagement with a friction clutch pack. Shifting from one speed ratio to another is performed automatically by a transmission controller. The controller applies a clutch associated with the current speed ratio, i.e., the offgoing clutch, and releases a clutch associated with a desired new speed ratio, i.e., the oncoming clutch. Precise knowledge of various control values of the offgoing and oncoming clutches in a shift maneuver is essential for optimal control and feel of the shift event.